Expert Makes Case for Hypofractionation in Prostate Cancer

Caroline Seymour

Published: Monday, Mar 19, 2018

Howard M. Sandler, MD

Guidelines in development from the American Society for Radiation Oncology (ASTRO), American Society of Clinical Oncology (ASCO), and the American Urological Association (AUA) will soon support for the use of hypofractionation in patients with prostate cancer, explains Howard M. Sandler, MD.

“We’re finalizing our guidelines for hypofractionation, and we're going to strongly endorse the use of moderate hypofractionation in 28 or 20 fractions for most patients with prostate cancer,” said Sandler, who is chairman of the guidelines panel.

The 20-fraction schedule can be given over 4 weeks; however, Sandler says that he prefers hypofractionation in 28 fractions over 5.5 weeks.

Clinical trials such as CHHiP, PROFIT, and RTOG 0415 were integral in demonstrating the effectiveness of hypofractionation in select patients, he added, as they randomized men to hypofractionation of 20 and 28 fractions compared with standard fractionation.

In an interview during the 2018 OncLive® State of the Science Summit™ on Genitourinary Cancers, Sandler, chair, Department of Radiation Oncology, Ronald H. Bloom Family Chair in Cancer Therapeutics, director, Samuel Oschin Comprehensive Cancer Institute, and professor of radiation oncology, Cedars-Sinai Medical Center, discussed the emergence of hypofractionation as a viable treatment approach for patients with prostate cancer.

OncLive: What developments have there been in the area of radiation oncology in prostate cancer?

Sandler: One of the major trends in prostate cancer is a move toward hypofractionation. In treatment, we’ll use fewer radiation fractions than we used in the past. We would use up to 45 treatments over 9 weeks. That is a long time for individuals to come in every day for radiation therapy treatment. We are excited about the studies published in 2016 and 2017 that showed equivalent outcomes between dramatically shorter regimens and standard fractionation. The 2 regimens that were studied were 20 and 28 fraction regimens. Both studies were compared head to head with standard fractionation and were noninferior to one another.

It's led to the widespread adoption of shorter and more convenient approaches without increasing side effects. It also reduces the overall healthcare expenditures in a patient’s treatment.

Can you detail some of the trials that have demonstrated its success?

Over 6000 patients have been randomized to moderate hypofractionation. The largest trial is the phase III CHHiP trial from the United Kingdom that randomized men to either standard radiation fractionation or 2 hypofractionation arms of either 20 or 19 fractions. The 19-fraction arm was inferior. There may not have been enough radiation in the 19-fraction approach, but the 20-fraction approach was the equivalent to standard fractionation.